Impact indicator

ABSTRACT

An impact indicator includes a first member having a reservoir for holding an indicator fluid; a second member couplable to the first member; and a third member disposed between an opening of the reservoir and the second member. Responsive to receiving a predetermined level of impact, at least a portion of the indicator fluid exits the reservoir, and wherein the third member causes the portion of the indicator fluid to be distributed across a surface of the first member adjacent the opening and facing the third member, the portion of the indicator fluid located on the surface of the first member providing a visual indication of the received predetermined level of impact.

BACKGROUND

During manufacturing, storage or transit, many types of objects need tobe monitored due to the sensitivity or fragility of the objects. Forexample, some types of objects may be susceptible to damage if droppedor a significant impact is received. Thus, for quality control purposesand/or the general monitoring of transportation conditions, it isdesirable to determine and/or verify the environmental conditions towhich the object has been exposed.

BRIEF SUMMARY

According to one aspect of the present disclosure, a device andtechnique for impact detection and indication is disclosed. The impactindicator includes a first member having a reservoir for holding anindicator fluid; a second member couplable to the first member; and athird member disposed between an opening of the reservoir and the secondmember. Responsive to receiving a predetermined level of impact, atleast a portion of the indicator fluid exits the reservoir, and whereinthe third member causes the portion of the indicator fluid to bedistributed across a surface of the first member adjacent the openingand facing the third member, the portion of the indicator fluid locatedon the surface of the first member providing a visual indication of thereceived predetermined level of impact

According to another embodiment of the present disclosure, an impactindicator includes a first member having a reservoir for holding anindicator fluid; a second member couplable to the first member; and athird member disposed at least partially between the first and secondmembers. Responsive to receiving a predetermined level of impact, theindicator fluid moves from the reservoir to an interface formed byopposing surfaces of the first and third members located adjacent to theopening of the reservoir, the indicator fluid wicking into the interfaceto provide a visual indication of the received predetermined level ofimpact.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a more complete understanding of the present application, theobjects and advantages thereof, reference is now made to the followingdescriptions taken in conjunction with the accompanying drawings, inwhich:

FIG. 1A is a diagram illustrating an exploded assembly view of anembodiment of an impact indicator according to the present disclosure;

FIG. 1B is a diagram illustrating an exploded assembly section view ofthe impact indicator illustrated in FIG. 1A according to the presentdisclosure;

FIG. 2A is a diagram illustrating an assembled view of the impactindicator of FIGS. 1A and 1B according to the present disclosure;

FIG. 2B is a diagram illustrating an assembled section view of theimpact indicator illustrated in FIGS. 1A, 1B and 2A according to thepresent disclosure;

FIGS. 3A-3D are diagrams illustrating various stages of impactactivation of the impact indicator illustrated in FIGS. 1A, 1B, 2A and2B according to the present disclosure;

FIG. 4A is a diagram illustrating an exploded assembly section view ofanother embodiment of an impact indicator according to the presentdisclosure;

FIG. 4B is a diagram illustrating an assembled section view of theimpact indicator illustrated in FIG. 4A according to the presentdisclosure;

FIG. 4C is a diagram illustrating an enlarged view of a portion of theimpact indicator illustrated in FIG. 4B according to the presentdisclosure;

FIGS. 5A-5D are diagrams illustrating various stages of impactactivation of the impact indicator illustrated in FIGS. 4A, 4B and 4Caccording to the present disclosure;

FIG. 6 is a diagram illustrating an exploded assembly view of anotherembodiment of an impact indicator according to the present disclosure;

FIG. 7A is a diagram illustrating a perspective assembled view ofanother embodiment of an impact indicator according to the presentdisclosure;

FIG. 7B is a diagram illustrating a top view of the impact indicatorillustrated in FIG. 7A;

FIG. 7C is a diagram illustrating an assembled section view of theimpact indicator illustrated in FIGS. 7A and 7B according to the presentdisclosure;

FIG. 8A is a diagram illustrating a perspective view of a base member ofanother embodiment of an impact indicator according to the presentdisclosure;

FIG. 8B is a diagram illustrating a top assembled view of the impactindicator illustrated in FIG. 8A; and

FIG. 8C is a diagram illustrating an assembled section view of theimpact indicator illustrated in FIGS. 8A and 8B according to the presentdisclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure provide a device and technique forimpact detection and indication. According to one embodiment, an impactindicator includes a first member having a reservoir for holding anindicator fluid; and a second member couplable to the first member overthe reservoir and configured to form a capillary gap between at least aportion of an interface between the first and second members. Responsiveto receiving a predetermined level of impact, the indicator fluid movesfrom the reservoir to the interface between the first and second membersand wicks into the capillary gap via capillary action, the indicatorfluid disposed within the capillary gap providing a visual indication ofthe received predetermined level of impact. Embodiments of the presentdisclosure enable impact and/or acceleration event detection utilizing apassive, small/compact indicator. Embodiments of the present disclosurealso provide a relatively large indicating area for a visual indicationof impact detection. Embodiments of the present disclosure furtherenable impact detection utilizing a relatively, thin, compact indicatordesign.

With reference now to the Figures and in particular with reference toFIGS. 1A, 1B, 2A and 2B, exemplary diagrams of an impact indicator 10are provided in which illustrative embodiments of the present disclosuremay be implemented. In FIGS. 1A, 1B, 2A and 2B, impact indicator 10 is aportable device configured to be affixed to or disposed within atransport container containing an object of which impact and/oracceleration events associated therewith are to be monitored.Embodiments of impact indicator 10 monitor whether an object has beenexposed to an impact or some level of an acceleration event duringmanufacturing, storage and/or transport of the object. In someembodiments, impact indicator 10 may be affixed to a transport containerusing, for example, adhesive materials, permanent or temporaryfasteners, or a variety of different types of attachment devices. Thetransport container may include a container in which a monitored objectis loosely placed or may comprise a container of the monitored objectitself. It should be appreciated that the above examples are onlyexemplary and are not intended to assert or imply any limitation withregard to the environments in which different embodiments of the impactindicator of the present disclosure may be implemented.

FIG. 1A is a diagram illustrating an exploded assembly view of impactindicator 10, and FIG. 1B is a diagram illustrating an exploded,sectioned assembly view of impact indicator 10 of FIG. 1A. FIG. 2A is adiagram illustrating an assembled view of impact indicator 10 of FIGS.1A and 1B, and FIG. 2B is a diagram illustrating a sectioned assembledview of impact indicator 10 of FIGS. 1A, 1B and 2A. In the embodimentillustrated in FIGS. 1A, 1B, 2A and 2B, impact indicator 10 comprises abase member 12 and a cover member 14. Base member 12 is insertable intoa cavity 16 formed in cover member 14. For example, in the illustratedembodiment, cover member 14 comprises a hat-shaped cover member 14having an annular base 18 transitioning into a cylindrical body 20having a vertical wall 22 and a closed top wall 24. Vertical wall 22 andtop wall 24 form a cylindrically-shaped cavity 16 for receiving at leasta portion of base member 12 therein. However, it should be understoodthat cover member 14 and/or cavity 16 may be of another shape (e.g.,non-cylindrical). In some embodiments, cover member 14 and/or basemember 12 may be constructed from a transparent, translucent and/orsemi-opaque material to enable visibility therethrough. As will bedescribed in greater detail below, in some embodiments, cover member 14is constructed and/or otherwise formed to enable visibility therethrough(e.g., through top wall 24) of an indicator fluid that, if visible, isan indication that impact indicator 10 has been subjected to and/orotherwise experienced a predetermined level of impact or accelerationevent. Although in some embodiments cover member 14 may be constructedas a single, unitary structure, it should be understood that covermember 14 may be formed from multiple components joined together.Further, it should be understood that various portions of cover member14 may be opaque, masked, and/or otherwise configured while otherportions of cover member 14 may be unmasked, clear, transparent,translucent and/or semi-opaque. For example, in some embodiments, base18 and wall 22 may be opaque while top wall 24 is translucent.

Base member 12 comprises a sidewall 30, an upper wall 32 and a reservoir34 extending downwardly from a surface 36 of upper wall 32 into a bodyportion 38 of base member 12. Reservoir 34 is formed for holding orcontaining therein an indicator fluid 40 that is used to provide anindication in response to impact indicator 10 being subjected to and/orotherwise experiencing a predetermined level of impact or accelerationevent. Reservoir 34 may be cylindrical or non-cylindrical. Base member12 is formed having a shape and/or configuration complementary to cavity16 to enable at least a portion of base member 12 to be slidablyinserted into cavity 16 of cover member 14. In some embodiments,sidewall 30 is formed having a tapered and/or angled wall configurationextending outwardly away from body portion 38 in a direction fromsurface 36 to surface 42 such that, upon insertion of base member 12into cavity 16, sidewall 30 is slightly compressed inwardly toward bodyportion 38 from vertical wall 22 of cover member 14 to provide acompression seal between base number 12 and cover member 14 forpreventing an escape of indicator fluid 40 from impact indicator 10.However, it should be understood that other methods and/or techniquesmay be used to provide a seal to prevent indicator fluid 40 from exitingimpact indicator 10 (e.g., an o-ring, epoxy seal, or other type ofsealing element or technique may be used between base member 12 andcover member 14).

In operation, base member 12 is inserted into cavity 16 of cover member14 and forms a capillary gap at an interface between surface 36 of basemember 12 and an interior surface 46 of the top wall 24 of cover member14. In some embodiments, surface 36 is formed having a matted surfacefinish such that surface irregularities corresponding to the mattedsurface finish of surface 36 form capillary gap 44 between surface 36and surface 46. For example, in some embodiments, when assembled, basemember 12 is inserted into cavity 16 such that surface 36 is placed intocontact with surface 46. The surface irregularities of surface 36 formcapillary gap 44 between surface 36 and surface 46. It should also beunderstood that surface irregularities on surface 46 may also beutilized to form capillary gap 44. Additionally, it should be understoodthat in some embodiments, base member 12 may be secured to cover member14 at a certain location or position to form capillary gap 44 of adesired size. For example, in some embodiments, cover member 14 and/orbase member 12 may be formed with a lip, ridge, tab, or other element toposition base member 12 relative to cover member 14 such that surface 36is located at a desired distance from surface 46 to form capillary gap44 of a desired size. However, it should be understood that othermethods may be used to retain base member 12 at a certain positionwithin cavity 16 to form capillary gap 44 of a desired dimension. Insome embodiments, capillary gap 44 is sized to be between 0.001 and0.005 inches; however, it should be understood that other sizes, greateror smaller, of capillary gap 44 may be used (e.g., based at least partlyon a viscosity of indicator fluid 40, surface variations on surfaces 36and 46, etc.).

In the embodiment illustrated in FIGS. 1B and 2B, cover member 14includes a plurality of retention elements 50 that may be used to retainbase member 12 within cavity 16 and coupled to cover member 14. Forexample, in some embodiments, retention elements 50 may be heat stakedto extend over a portion of surface 42 of base member 12 to retain basenumber 12 in a fixed position within cavity 16. However, it should beunderstood that other types of devices and/or techniques may be used tofixedly couple base member 12 to cover member 14 (e.g., tabs, threadedassembly, snap-fit, etc.).

In some embodiments, indicator fluid 40 comprises a colored or dyedfluid to enable a visual indication that impact indicator 10 has beensubjected to a predetermined level of impact or acceleration event. Forexample, in operation, indicator fluid 40 is held or retained inreservoir 34 by surface tension of indicator fluid 40. The indicatorfluid 40 forms a meniscus with an interior wall surface 54 of reservoir34. In response to receiving and/or experiencing a sufficient magnitudeof impact or acceleration event, the meniscus contorts or ruptures,thereby causing at least a portion of indicator fluid 40 to splash orflow out of reservoir 40 toward surface 46 and/or capillary gap 44. Uponcontact of indicator fluid 40 with surface 46 or indicator fluid 40reaching an edge of the capillary gap 44 interface (e.g., near an edgeor boundary of reservoir 34 with capillary gap 44), capillary gap 44causes indicator fluid 42 wick into capillary gap 44 by capillary action(e.g., because of inter-molecular attractive forces between the fluidand solid surrounding surfaces) and substantially fill the interfacebetween surfaces 36 and 46. As described above, in some embodiments, topwall 24 of cover member 14 is formed of a translucent or transparentmaterial such that indicator fluid 40 is externally visible whenresiding within capillary gap 44 at the interface between surfaces 36and 46, thereby providing a visual indication of an impact oracceleration event. In some embodiments, a mouth of reservoir 34 at ornear surface 36 may be slightly drafted, rounded or angled to provide adefined path for indicator fluid 42 to wick into capillary gap 44 (e.g.,at approximately one to four degrees or another suitable draft angle orshape).

The amount of surface tension of indicator fluid 40 to reservoir 34 canbe controlled to result in a release of indicator fluid 40 (e.g., adistortion or rupture of a meniscus of indicator fluid 40 with surface54) in response to a certain impact or acceleration level or magnitude.For example, a material of base member 12 (e.g., the material formingreservoir 34), the size or diameter of reservoir 34, and/or a viscosityof indicator fluid 40 may be selected to have a desired surface tensionto reservoir 34, thereby needing a certain magnitude of impact oracceleration event to cause a distortion or disruption of the meniscusof indicator fluid 40 to cause indicator fluid 40 to wick into capillarygap 44 between surfaces 36 and 46. In some embodiments, indicator fluid40 may comprise a mixture or combination of water, ethylene glycol,lithium chloride, and a desired colorant. The ethylene glycol functionsto lower the freezing point of indicator fluid 40 for cold temperatureapplications. The lithium chloride functions to lower the vapor pressureof indicator fluid. However, it should be understood that other fluidsor combinations of fluids may be used for indicator fluid 40. Forexample, as the bore size/diameter of reservoir 34 is reduced, a highermagnitude of acceleration is generally needed to rupture a meniscuscorresponding to indicator fluid 40 in contact with surface 54 andrelease indicator fluid 40 toward capillary gap 44. For example, thereare generally two factors that influence indicator fluid 40's responseto acceleration—viscosity and surface tension. Viscosity influences afluid's ability to quickly deform and change shape. Surface tensioninfluences a fluid's affinity and adhesion to itself or an externalsurface. There is generally a finite range over which the viscosity of afluid can be varied and significantly affect the activation or impactsensitivity. For example, in some embodiments, this range may beapproximately between twenty centistokes and eighty centistokes,depending on the internal bore diameter of reservoir 34. However, itshould be understood that other viscosities or viscosity ranges may beutilized based on a selected bore size of reservoir 34.

In some embodiments of the present disclosure, the following classes offluids may also be utilized for indicator fluid 40: a) synthetichydraulic fluids; b) silicone oils; and/or c) polypropylene glycol.These fluids promote higher impact sensitivities. For example, synthetichydraulic fluids were originally developed as a non-flammablealternative to oil-based hydraulic fluid. Synthetic hydraulic fluids areavailable in various controlled viscosities. Many synthetic hydraulicfluids have a very high viscosity index. Viscosity index is a numberthat characterizes how the viscosity of a fluid changes due totemperature changes. Viscosity index is calculated from the measuredviscosity at 40° C. and 100° C. using ASTM Method D 2270. Synthetichydraulic fluids are stable and have moderately low freezing points.

Silicone oils (polymerized siloxanes) are generally considered not to besilicone but rather silicon analogues of carbon based organic compounds,and can form (relatively) long and complex molecules based on siliconrather than carbon. Chains are formed of alternating silicon-oxygenatoms ( . . . Si—O—Si—O—Si . . . ) or siloxane, rather than carbon atoms( . . . C—C—C—C . . . ). Other species attach to the tetravalent siliconatoms, not to the divalent oxygen atoms which are fully committed toforming the siloxane chain. A typical example is polydimethylsiloxane,where two methyl groups attach to each silicon atom to form(H3C)[SiO(CH3)2]nSi(CH3)3. The carbon analogue would be an alkane (e.g.dimethylpropane C5H12 or (H3C)[C(CH3)2](CH3)). Silicone oils have anextremely high viscosity index and are available in controlledviscosities. Silicone oils are very inert, stable and have very lowfreezing points.

Polypropylene glycol or polypropylene oxide is generally considered tobe the polymer of propylene glycol. Chemically, polypropylene glycol isa polyether. The term polypropylene glycol or PPG is reserved for a lowto medium range molar mass polymer when the nature of the end-group,which is usually a hydroxyl group, affect polymer properties. The term“oxide” is used for a high molar mass polymer when end-groups no longeraffect polymer properties. Polypropylene glycol is available in variousmolecular weights, which in turn provides for various viscosities.Polypropylene glycol also has a very low freezing point, is easilycolored, and has a moderate viscosity index.

Thus, in some embodiments of the present disclosure, synthetic hydraulicfluids, silicone oils, and/or polypropylene glycol may be selected invarious controlled viscosities for indicator fluid 40. Further,synthetic hydraulic fluids, silicone oils, and/or polypropylene glycolmay also be blended to form indicator fluid 40 having a precise desiredviscosity. Thus, embodiments of the present disclosure enable theselection and/or use of different particular viscosity fluids that maybe used with a particular size of reservoir 34 to provide a variety ofdifferent impact sensitivities for impact indicator 10.

FIGS. 3A-3D are diagrams illustrating migration of indicator fluid 40within capillary gap 44 by capillary action in response to impactindicator 10 being subjected to a sufficient magnitude of impact oracceleration event. Referring to FIG. 3A, impact indicator 10 isillustrated in a non-activated state (with cover member 14 depicted inphantom lines) such that indicator fluid 40 is located/retained withinreservoir 34. For ease of description and clarity, impact indicator 10is illustrated without cover member 14 in FIGS. 3B-3D; however, itshould be understood that, in operation, cover member 14 would becoupled to base member 12 to form the capillary gap interface for impactindication. In FIG. 3B, in response to impact indicator 10 beingsubjected to a sufficient magnitude of impact or acceleration event, themeniscus of indicator fluid 40 with reservoir 34 is contorted ordisrupted causing indicator fluid 40 to reach an interface common tocapillary gap 44 and wick into and across capillary gap 44 by capillaryaction at the interface between surfaces 36 and 46. Referring to FIGS.3C and 3D, the capillary action caused by capillary gap 44 causesindicator fluid 40 to wick into and fill (or substantially fill) theinterface between surfaces 36 and 46 extending outwardly toward aperipheral boundary 56 of capillary gap 44. As described above, in someembodiments, top wall 24 of cover member 14 is formed of a transparentor translucent material such that the interface between surfaces 34 and46 is externally visible, thereby enabling an external visual indicationof impact indicator 10 activation by the visibility of indicator fluid40 extending substantially across the interface between surfaces 36 and46.

FIGS. 4A-4C are diagrams illustrating another embodiment of impactindicator 10. In the illustrated embodiment, upper wall 32 of basemember 12 is formed having a recess 60 for receiving acomplementary-shaped disc member 62 therein. Recess 60 is formed tocreate a gap 64 between surface 36 of base member 12 and surface 46 ofcover member 14 to enable disc member 62 to float within gap 64. In someembodiments, disc member 62 comprises a flexible material to enable discmember 62 to flexibly conform to surface 36 in response to indicatorfluid 40 being located at the interface between surface 36 and a surface66 of disc member 62. In some embodiments, disc member 62 may beconstructed from plastic, polyester material (such as Mylar™ orDuralar™), cellophane or another type of flexible material to enabledisc member 62 to conform (substantially evenly) to surface 36 inresponse to indicator fluid 40 wicking across the interface betweensurfaces 36 and 66. Referring to FIG. 4C, upper wall 32 may be formedhaving an elevated portion 68 that, when in contact with surface 46 ofcover member 14, forms a desired size gap 64 for disc member 62, therebycreating a desired size capillary gap between disc member 62 and surface36. However, it should be understood that other techniques or methodsmay be used to form a desired gap or cavity for retaining disc member 62therein between surfaces 36 and 46 (e.g., a recess formed in top wall 24of cover member 14).

In operation, in response to receipt of a sufficient magnitude of impactor acceleration event, indicator fluid 40 reaches the interface betweendisc member 62 and surface 36 and begins wicking across and/or into thecapillary gap interface between surfaces 36 and 66 via capillary action.As a result of indicator fluid 40 wicking into the interface betweensurfaces 36 and 66, the capillary action of indicator fluid 40 pullsdisc member 62 toward surface 36 and thereby evenly distributes (orsubstantially evenly distributes) indicator fluid 40 across theinterface between surfaces 36 and 66. In some embodiments, disc member62 may be formed from a translucent, transparent, semi-opaque or othermaterial to enable indicator fluid 40 to be visible therethrough toprovide a visual indication of activation of impact indicator 10.

FIGS. 5A-5D are diagrams illustrating migration of indicator fluid 40within the capillary gap interface formed between surface 36 and discmember 62 corresponding to the impact indicator 10 illustrated in FIGS.4A-4C in response to impact indicator 10 being subjected to a sufficientmagnitude of impact or acceleration event. Referring to FIG. 5A, impactindicator 10 is illustrated in a non-activated state (with cover member14 depicted in phantom lines) such that indicator fluid 40 islocated/retained within reservoir 34. In some embodiments, disc member62 may prevent an external visual perception of indicator fluid 40 whileretained in reservoir 34. For ease of description and clarity, impactindicator 10 is illustrated without cover member 14 in FIGS. 5B-5D;however, it should be understood that, in operation, cover member 14would be coupled to base member 12 to retain disc member 62 within gap64. In FIG. 5B, in response to impact indicator 10 being subjected to asufficient magnitude of impact or acceleration event, the meniscus ofindicator fluid 40 with reservoir 34 is contorted or disrupted causingindicator fluid 40 to reach the interface between surface 36 and surface66 of disc member 62 and wick into and across the interface betweensurfaces 36 and 66 by capillary action. Referring to FIGS. 5C and 5D,the capillary action of indicator fluid 40 causes disc member 62 to flexdownwardly slightly toward surface 36 to thereby cause indicator fluid40 to wick into, fill and be dispersed across the interface betweensurfaces 36 and 66. As described above, in some embodiments, disc member62 and top wall 24 of cover member 14 are formed of a translucent and/ortransparent material such that the interface between surfaces 34 and 66is externally visible, thereby enabling an external visual indication ofimpact indicator 10 activation by the visibility of indicator fluid 40extending substantially across the interface between surfaces 36 and 66toward a peripheral boundary of disc member 62 and/or gap 64.

FIG. 6 is a diagram illustrating another embodiment of an impactindicator 70 in accordance with the present disclosure. In theembodiment illustrated in FIG. 6, impact indicator 70 includes a basemember 72 and a cover member 74. Base member 72 includes a reservoir 76for retaining indicator fluid 40 therein. In the illustrated embodiment,cover member 74 is constructed from a transparent, translucent orsemi-opaque material to enable visibility therethrough to detectindicator fluid 40 when located within a capillary gap interface formedbetween a surface 78 of base member 72 and an interior surface 80 ofcover member 74 facing surface 78. In the embodiment illustrated in FIG.6, a cover 84 is placed onto an exterior facing surface 86 of covermember 74 in a position corresponding to a location of reservoir 76. Insome embodiments, cover 84 may comprise an adhesive-backed label orother type of cover element that may be adhered to surface 86 and/orotherwise affixed to cover member 74 to prevent visibility of indicatorfluid 40 while located within reservoir 76.

As described above in connection with FIGS. 1A, 1B, 2A and 2B, covermember 74 is placed over and onto base member 72 and secured theretosuch that surface 78 is brought into contact with and/or is otherwiseplaced in close proximity to interior surface 80 of cover member 74 tocreate a desired capillary gap between surfaces 78 and 80. In responseto receiving a sufficient magnitude of impact or acceleration event, ameniscus of indicator fluid 40 with an interior surface or wall ofreservoir 76 is distorted or disrupted causing a droplet or portion ofindicator fluid 40 to contact surface 80 and/or otherwise come intocontact with an edge of the interface formed between surfaces 78 and 80.The capillary gap formed between surfaces 78 and 80 cause indicatorfluid 40 to wick into the capillary gap via capillary action and migrateacross the interface formed between surfaces 78 and 80. As indicatorfluid 40 wicks across the interface formed between surfaces 70 and 80,indicator fluid 40 extends beyond a boundary covered by cover 84 andbecomes visible through surface 86 of cover member 74, thereby providinga visual indication of impact detection.

FIGS. 7A-7C are diagrams illustrating another embodiment of an impactindicator 90 in accordance with the present disclosure. FIG. 7A is adiagram illustrating a perspective view of impact indicator 90 partiallysectioned (corresponding to line 7A-7A of FIG. 7B), and FIG. 7B is adiagram illustrating a top view (unsectioned) of impact indicator 90illustrated in FIG. 7A. FIG. 7C is a diagram illustrating a section viewof impact indicator 90 illustrated in FIGS. 7A and 7B taken along theline 7C-7C of FIG. 7B. In the embodiment illustrated in FIGS. 7A-7C,impact indicator 90 includes a base member 92 and a cover member 94.Base member 92 includes a reservoir 96 for retaining or holding thereinindicator fluid 40. As described above, in some embodiments, covermember 94 is constructed from a transparent, translucent and/orsemi-opaque material to enable at least partial visibility therethrough.Base member 92 and cover member 94 are constructed to facilitateinsertion of base member 92 at least partially into and within a cavity98 formed in cover member 94 to create a capillary gap interface 100between a top surface 102 of base member 92 and an interior surface 104of cover member 94. In the illustrated embodiment, surfaces 102 and 104are arcuately formed having an arched or curved profile to provide acurved capillary gap interface 100. As described above in connectionwith FIGS. 1A, 1B, 2A and 2B, surfaces 102 and/or 104 may be formedhaving a matted surface or other surface finish creating irregularitiesin the respective surfaces to form capillary gap interface 100. Basemember 92 and/or cover member 94 may also be constructed to secure basemember 92 at a defined position within cavity 98 to define capillary gapinterface 100 with a desired dimension (e.g., by using tabs, surfacedeviations, a raised edge for lip, etc.).

As described above, in response to being exposed to a sufficientmagnitude of impact or acceleration even, a meniscus of indicator fluid40 with reservoir 96 is distorted or ruptured causing at least a portionof indicator fluid 40 to contact surface 104 and/or otherwise come intocontact with an edge of capillary gap interface 100. The size ofcapillary gap interface 100 causes indicator fluid 40 to wick intocapillary gap interface 100 via capillary action. Indicator fluid 40migrates into and extends outwardly away from reservoir 96 in capillarygap interface 100 toward an outward peripheral boundary 106 of capillarygap interface 100. As indicator fluid 40 wicks into and/or otherwiseextends across or through capillary gap interface 100 toward boundary106, indicator fluid 40 is visible through cover member 94, therebyproviding a visual indication of impact detection.

FIGS. 8A-8C are diagrams illustrating another embodiment of an impactindicator 110 in accordance with the present disclosure. FIG. 8A is adiagram illustrating an embodiment of a base member 112 of impactindicator 110. FIG. 8B is a diagram illustrating impact indicator 110 inan activated state. FIG. 8C is a diagram illustrating a section view ofimpact indicator 110 illustrated in FIGS. 8B taken along the line 8C-8Cof FIG. 8B. In the embodiment illustrated in FIGS. 8A-8C, impactindicator 110 includes base member 112 and a cover member 114. Basemember 112 includes a reservoir 116 for retaining or holding thereinindicator fluid 40. As described above, in some embodiments, covermember 114 is constructed from a transparent, translucent and/orsemi-opaque material to enable at least partial visibility therethrough.

In the illustrated embodiment, base member 112 is formed having a cavity120 formed in an upwardly facing direction for receiving insertiontherein of cover member 114. Base member 112 also includes rib members122 extending radially outward from reservoir 116 toward an outwardperipheral boundary 124 of an upwardly facing pedestal portion 126 ofbase member 112. A sidewall 130 of base member 112 is formed with anannular recess 132 for receiving therein an annular tab 134 formed oncover member 114 to facilitate a snap-fit coupling of cover member 114to base member 112 within cavity 120. However, it should be understoodthat other methods or techniques may be used to secure cover member 114to base member 112.

Base member 112 and cover member 114 are constructed to facilitateinsertion of cover member 114 at least partially into and within cavity120 of base member 112 and extending over reservoir 116 such that acapillary gap interface 140 is formed between a top surface 142 of ribmembers 122 and an interior surface 144 of cover member 114. Asdescribed above in connection with FIGS. 1A, 1B, 2A and 2B, surfaces 142and/or 144 may be formed having a matted surface or other surface finishcreating irregularities in the respective surfaces to form capillary gapinterface 140. The location of recess 132 and tab 134 may also beconfigured to secure cover member 114 at a defined position withincavity 120 to define capillary gap interface 140 with a desireddimension.

As described above, in response to being exposed to a sufficientmagnitude of impact or acceleration even, a meniscus of indicator fluid40 with reservoir 116 is distorted or ruptured causing at least aportion of indicator fluid 40 to contact surface 144 and/or otherwisecome into contact with an edge of capillary gap interface 140. The sizeof capillary gap interface 140 causes indicator fluid 40 to wick intocapillary gap interface 140 via capillary action. Indicator fluid 40migrates into and extends outwardly away from reservoir 116 in capillarygap interface 140 toward boundary 124 of capillary gap interface 140. Inthe event indicator fluid 40 enters spaced areas 150 located between ribmembers 122, the capillary action caused by capillary gap 140 will causethe indicator fluid 40 to be wicked out of such spaced areas 150 intothe capillary gap 140 areas common to surfaces 142 of rib members 122.As indicator fluid 40 wicks into and/or otherwise extends across orthrough capillary gap interface 140 toward boundary 124, indicator fluid40 is visible through cover member 114, thereby providing a visualindication of impact detection.

Thus, embodiments of the present disclosure enable impact and/oracceleration event detection utilizing a passive, small/compactindicator. Embodiments of the present disclosure provide a relativelylarge indicating area for a visual indication of impact detection.Embodiments of the present disclosure also enable impact detectionutilizing a relatively, thin, compact indicator design. Embodiments ofthe present invention also enable omnidirectional impact or accelerationevent detection and indication (e.g., impact or acceleration events in anumber of different directions, including directional component vectordirections). For example, impact or acceleration events may be detectedin directions parallel to or axially aligned with an axis orlongitudinal direction of reservoir 34 (e.g., perpendicular to surface36), directions perpendicular or radially normal to an axis orlongitudinal direction of reservoir 34 (e.g., in a direction parallel toa plane of surface 36) and in other directions based on directionalvector component magnitudes.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present disclosure has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the disclosure in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the disclosure. Theembodiment was chosen and described in order to best explain theprinciples of the disclosure and the practical application, and toenable others of ordinary skill in the art to understand the disclosurefor various embodiments with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. An impact indicator, comprising: a first memberhaving a reservoir for holding an indicator fluid; a second membercouplable to the first member; and a third member disposed between anopening of the reservoir and the second member; and wherein, responsiveto receiving a predetermined level of impact, at least a portion of theindicator fluid exits the reservoir, and wherein the third member causesthe portion of the indicator fluid to be distributed across a surface ofthe first member adjacent the opening and facing the third member, theportion of the indicator fluid located on the surface of the firstmember providing a visual indication of the received predetermined levelof impact.
 2. The impact indicator of claim 1, wherein the indicatorfluid comprises a synthetic hydraulic fluid.
 3. The impact indicator ofclaim 1, wherein the indicator fluid comprises a silicone oil fluid. 4.The impact indicator of claim 1, wherein the indicator fluid comprises apropylene glycol fluid.
 5. The impact indicator of claim 1, wherein aninternal bore size of the reservoir and a viscosity of the indicatorfluid are selected to obtain a desired activation sensitivity for thepredetermined level of impact.
 6. The impact indicator of claim 1,wherein the third member comprises a flexible member.
 7. The impactindicator of claim 1, wherein the second member comprises a materialenabling visibility of the indicator fluid when located on the surfaceof the first member.
 8. The impact indicator of claim 1, wherein theviscosity of the indicator fluid is between 20 and 80 centistokes. 9.The impact indicator of claim 1, wherein the third member comprises amaterial enabling visibility of the indicator fluid when located on thesurface of the first member.
 10. An impact indicator, comprising: afirst member having a reservoir for holding an indicator fluid; a secondmember couplable to the first member; and a third member disposed atleast partially between the first and second members; and wherein,responsive to receiving a predetermined level of impact, the indicatorfluid moves from the reservoir to an interface formed by opposingsurfaces of the first and third members located adjacent to the openingof the reservoir, the indicator fluid wicking into the interface toprovide a visual indication of the received predetermined level ofimpact.
 11. The impact indicator of claim 10, wherein the second membercomprises a material enabling visibility of the indicator fluid when theindicator fluid is within the interface.
 12. The impact indicator ofclaim 10, wherein the indicator fluid comprises at least one of asynthetic hydraulic fluid, a silicone oil fluid and propylene glycolfluid.
 13. The impact indicator of claim 10, wherein a diameter of thereservoir and a viscosity of the indicator fluid are selected to obtaina desired activation sensitivity for the predetermined level of impact.14. The impact indicator of claim 10, wherein the viscosity of theindicator fluid is between 20 and 80 centistokes.
 15. The impactindicator of claim 10, wherein, responsive to the indictor fluidentering the interface, the indicator fluid migrates toward a peripheralboundary of the interface.
 16. The impact indicator of claim 15, whereinthe indicator fluid migrates in at least two different directions fromthe opening toward the peripheral boundary of the interface.
 17. Theimpact indicator of claim 10, wherein the third member comprises amaterial enabling visibility of the indicator fluid when located in theinterface.